Essential to California’s Financial and Environmental Future: a Healthy Delta
The San Francisco Bay Delta, a freshwater body formed where the Sacramento, San Joaquin and several smaller rivers meet, near the city of Stockton, is the largest natural estuary on the West Coast. It covers more than 1,100 square miles, an area about three times the size of the City of San Diego. It provides breeding grounds and habitat for a range of animals, including Chinook salmon and the endangered Delta smelt.
The Bay Delta's ecosystem has dramatically declined because of excessive water diversions, introduced nonnative invasive species, and water pollution.
Now the Bay Delta's future and function is threatened by a proposal to build a single tunnel that would divert millions of acre-feet of fresh water from above the Delta to parts below the estuary. Sierra Club California opposes the construction of the single tunnel project. Instead, we believe Californians should pursue a range of other strategies that together will sustainably meet water needs while protecting the environment.
It's the final countdown to the funding vote for the next phase of the Delta Tunnel! Join us to tell MWD not to waste $140m on the DeltaTunnel, an environmental disaster!
Get Involved
If you want to join the Delta Tunnel Campaign, sign up below:
For any questions about the campaign, email Caty Wagner (caty.wagner@sierraclub.org) about the Delta Tunnel project in Southern California, or Molly Culton (molly.culton@sierraclub.org) in Northern California.
Everyone is welcome to join. You don't need to have previous advocacy experience or be familiar with the Bay-Delta Tunnel project. We're looking forward to meeting you!
SF Bay Delta Fact Sheets
- The San Francisco Bay-Delta: California's Irreplaceable Resource
- Threats to the Bay-Delta: Underappreciated and Overused
- The Delta Tunnel: Not a Solution to Earthquakes and Sea Level Rise
- The Delta Tunnel: An Environmental Justice Debacle
- The Bay-Delta Estuary: Frequently Asked Questions
- The Delta Tunnel by the Numbers
- Map of Delta and CA Water Systems
- Hojas de hechos en Español: Sierra Club California Apoya Alternativas Razonables a los Túneles Gigantes de la Bahía de San Francisco-Delta
Position Papers and Other Relevant Documents
- Sierra Club California Smart Water Alternatives (2022), a whitepaper which outlines alternatives to the Delta Conveyance Project California should pursue to meet its water resiliency needs
- California Voter Attitudes on the Delta Tunnel Summary Memo (2021), a public opinion survey commissioned by Sierra Club California
- The Smart Alternative to Tunnel(s): A Sensible Water Management Portfolio (2019), a report written by the Sierra Club California Water Committee
- Clean, Sustainable and Reliable Water Supply: Alternatives to the Giant Bay Delta Tunnels (2013), a white paper produced by the Sierra Club California Water Committee
- Letter to Governor Brown, (2013) regarding Sierra Club California concerns about the giant bay delta tunnels
- Complaint filed against California Department of Water Resources (2020) regarding failure to address State Water Project’s threat to Bay Delta
- New Report Exposes Inaccuracies in Benefit Cost-Analysis of California's Delta Conveyance Project Press Release
CA Water Webinar Series
- Updates and Perspectives on Delta Projects
- The Bay Delta: A Threatened Resource
- Biodiversity and Water in the SF Bay
- The Delta Tunnel Project: Not a Solution for Southern California’s Water Needs
Stop the Delta Tunnel Series
- The Delta Conveyance Project Overview
- The Impact of the Delta Tunnel on Communities
- The Impact of the Delta Tunnel on Wildlife
- MWD 101
- DWR EIR Workshops & the Delta Tunnel
- Fisheries & the Delta Tunnels
- The Voluntary Agreements
- Harmful Algal Blooms (HABs)
- Preferential Rights & WSAP at MWD
- Sites Reservoir & Pacheco Dam
- Subsidence
- Voluntary Agreements
- Delta Tunnel (2020)
- SoCal Pure Water Recycling Facility
- Rain Barrels
- Pacific Institute's Report on Untapped Water Supply
- Pacheco Dam
- LA Aqueduct
- Dewatering
- Delta Tunnel 101
- Delta Tunnel & Valley Fever
- Cloud Seeding
- Central Valley Joint Venture & Motus Avium
- Carbon Capture & the Bay Delta
- Alternatives to the Delta Tunnel 2022
- Allensworth & the Levee Breach